Oil burner



Dec, 1, 1942. l A. J. FISHER 2,303,925

OIL BURNER Filed March 6, 1939 3 Sheets-Sheet 1 NoRs wJ. FwHliR Dec. -1,1942.

A. J. FISHER OIL BURNER Filed March 6, 1939 5 sheet -sheet 2 IIIWWIll/1%);

ANDRIEQV J. F\SHEZR I Dec. 1, 1942. M. FQISHER v 2,303,925

OIL BURNER Filed March 6, 1939 3 Sheets-Sheet 3 ANDREW J. Fusm-zR 'allelby means of an oil pressure regulator.

Patented Dec. 1, 1942 OIL BURNER Andrew J. Fisher, Baltimore County,Md., assignor to The C. M. Kemp Manufacturing Company, a corporation ofMaryland Application March 6, 1939, Serial No. 260,032

9 Claims.

This invention relates to an oil burner for industrial purposes, and ithas particular reference to an automatic air-adjusting burner suited forindirect firing, such as for galvanizing pots, drying ovens, potannealing, and the like, and it is adapted to be equipped with a burnerdischarging either a long or short flame depending upon the size andshape of the combustion space. The long flame type of burner isparticularly suited for recirculating furnace gases. high and its flamecontracted.

The burner is of such simplicity in construction and manufacture that itwill ordinarily not get out of order through long periods of use. It isdesigned to be adjustable to the furnace wall in the exact center of theopening provided, and it is also withdrawable therefrom for cleaning, orwhen not in use, or for changing the burners. Ordinarily about 50% ofthe air required for combustion is inspirated through the refractorytile 9 by the velocity of the air and oil stream. Means are provided forcontrolling the amount of this induced air. In the burner of thisinvention the bon. The burner is designed for mechanical atomizationwhich allows the flow of oil to be controlled by pressure, and this inturn allows for the control of a plurality of burners in par- The use ofoil pressure makes certain precision control arrangements practical,which would not otherwise 'be posssible of attainment, by controllingthe flow of oil by means of valves.

Other advantages of the burner will be apparent from the followingdescription, and the accompanying drawings forming a part hereof, and

in which similar numerals refer to similar parts throughout the severalviews:

Figure 1 is a partial vertical cross-sectional view of the short flameburner showing the automatic air control. Figure 2' is'a vertical viewof Figure 4 Figure 6' is a sectional view on line 66 of Figure I 5.Figure 7 is an end view of the burner shown in Figure 5.

The furnace I is shown having an opening 2 1n the refractory tile 3, andcoaxial with this open-.

Its velocity is attachments of double joint elbow 5, allow the burner tobe placed in the exact center of the opening 2. The refractories of thefurnace expanddiiferently from the steel framing of the furnace, andmake necessary. exact adjustments or the burner to maintain thisaccurate alignment. The valve It] is turned to open position when theburner is in use, and it is closed when the burner is shut off. Thesliding collar II on burner 4 is adjustable over the opening 2 toregulate-the air inspirated into the opening 2 by the air andoil-stream.

The burner proper comprises the: air entry pipe I2 which, at itsdischarge end, is constricted. as shown at l3, and this-constructiontends to converge the air in its discharge to a point just beyond theend of the burner. Coaxial with this pipe I2 a shielding tube I4 carriesthe oil tube 55. The oil tube I5 screws into enlarged sleeve I6 formingpart of the oil discharge head, and which is guided in shielding tube I4by webs I1,

and webs I8 maintain the coaxial relation of tube 7 54 in pipe I2. ScrewI9 in tube I4 slides in groove in to. prevent relative rotation of thesleeve I6 on tube I5. Sleeve I6 may have thereon an oil discharge nozzlefor short flames indicated at 2| or one for long flames indicated at 22.This nozzle in one longitudinal position substantially closes theairdischarge from the end of pipe I2, but upon the retraction of the nozzlea larger amount of air is discharged.

The burner is usually designed for the use of air at a comparatively lowpressure, and oil at a comparatively high pressure, which is preferablyheated to approximately 180 to 225 F. The amount of air dischargedthrough constricted opening I3 of pipe I2 is regulated by the oilpressure. The shielding tube I4, which prevents the cold air fromstriking the oil tube I5, has at one end an enlarged portion 23 fittingtightly upon the enlarged portion of air conductor 8 and. I2 and formingone side of the chamber 24. The other side of this chamber 2-4 is thediaphragm 2'5 firmly attached centrally to oil tube I5 by means ofcollar 26, washer 21 and nut 28. Collar 26 has therein radial openings29 connecting with similar openings 30 in tube I5. Washer and packing 3|allow longitudinal movement of tube I in tube 4 without appreciable lossof pressure. Tube I5 is held in a position to substantially close theair discharge outlet at constricted opening I3 by means of spring 32fitting in cover 33 for the diaphragm 25, the whole assembly being heldtightly in place on air pipes 8 and I2 by bolts 34. It will be apparentthat as the pressure of the oil discharging in the chamber 24 increases,the diaphragm will be pushed back against the spring 32, and the nozzles2| or 22 will be drawn backward, and the amount of air discharged frompipe l2 will thereby be increased precisely in proportion to theincrease in oil pressure, and consequently the oil discharged.

The short flame nozzle shown in Figures 1, 3 and 4 has an antistreamline outer section 35, and

. it is screwed into sleeve I6 by means of wrench openings 36. Thenozzle has a cylindrical center opening 37 stopping short of the end ofthe nozzle, as shown at 38, and in this end opening is a small hardeneddischarge nozzle 39 having a conical opening therethrough. Fitting inthe cylindrical opening 3'! is a square block 38, the edges of which areguided by the cylindrical opening. The end of this block toward thenozzle 39 has a cylindrical portion 40 thereon which has four slots 4|entering from its sides and which approach the center of the dischargenozzle 39 tangential to the large end of the conical opening through it,as shown in Figure 4. This end of the block 38' is held tightly againstthe discharge nozzle 39 by means of spring 42 fitting against theshoulder of the small oil opening 43 in sleeve I6. By means of thisstructure the oil enters from pipe |5, passing through opening 43 at acomparatively high pressure, and strikes the blunt end of block 38'which allows it to pass along the four sides of the block 38 down to thecylindrical portion 40 where it enters the tangential slots 4| fromwhich it obtains a rapid spiral motion, and being contracted by theconical hardened member 39, and discharges in atomized form from the endof the nozzle. When the flow of air passes the conical nozzle 2| a lowpressure area is created in front of th nozzle which creates in turn aflow of air toward the center of the nozzle from whence it radiates outto the main air stream. This back-drafting of the nozzle spreads themechanical oil atomization from a cone of about 60 to on of about 180",the diameter of which is the same as the diameter of the nozzle. Thiscreates a much finer degree of atomization than is otherwise obtainableby a straight mechanical atomizer and makes the oil burn in a shortbushy flame.

In the long flame form of nozzle the sleeve l6,

' at its discharge end, has an outwardly extending cup formation 42,into which may be screwed primary air nozzle 43' by means of wrenchholes 44. Oil discharge nozzle 45 is screwed into the sleeve l5 andbetween the two is placed a hardened fiow contracting member 46 beyondwhich the opening 4'! in the oil discharge nozzle 45 is enlarged. Inthis nozzle 45 is a pin 48 passing diametrically across the opening 47and immediately in front of the constricted opening in member 46. Theoil passing through this constricted opening at high pressure has thatpressure suddenly released, and at high temperature this sudden releasecauses the oil to foam. The degree of foaming of the oil is determinedby its temperature,

pressure, and viscosity. The striking of the pin deflects the oil streamand slows it to a uniform velocity in the opening 41. Axial openings 49in cup-shape member 42' allow the passage of air from air pipe I2through the circular opening in primary air discharge nozzle 43 andaround the atomized oil from th oil discharge nozzle 45. This primaryair opening is small. Its purpose is to carry the oil foam through theburner tile and into the furnace when the secondary air stream comingbetween constricted opening |3 in the air pipe l2 and th primary airnozzle 43', is shut off. This provides for a greater degree of turndownthan is possible without the use of primary air. The secondary airopening is designed to furnish the greater percentag of air. Its shapeis such that the air stream converges around the oil foam and primaryair to form a condensed mixture which makes the oil burn in a longflame.

It should be understood that various changes in form, proportions, andminor details of construction may be resorted to within the scope of theappended claims.

Having thus described the invention, what is desired to be secured byLetters Patent, is:

1. An oil burner comprising an air pipe having a constricted dischargeopening, an oil tube for the passage of oil therethrough under pressureand beinglongitudinally movable in said air pipe and arranged coaxiallytherewith and having thereon a discharge head closely fitting saidconstricted opening in one position and being movable to and from theopening, whereby the relative longitudinal position of said pipe andtube determines the rate of air discharge, a tube between said air pipeand oil tube to shield said oil tube from the air in said air pipe andhav ing guides therein adjacent the discharge end of said air pipe, thedischarg head on said oil tube extending rearwardly in said guides, oilatomizing means in said head discharging centrally of the air stream,and means for automatically moving said pipe and oil tube relativelylongitudinally upon variations in pressure of the oil passing throughsaid oil tube.

2. An oil burner comprising an air pip having a constricted dischargeopening, an oil tube for the passage of oil therethrough under pressureand being longitudinally movable in said air pipe and arranged coaxiallytherewith and having thereon a discharge head fitting closely saidconstricted opening in one position and being movable from the openingwhereby the relative longitudinal position of said pipe and tubedetermines the rate of air discharge, oil atomizing means in said headdischarging centrallyof the air stream and means for automaticallymoving said pipe and tube relatively longitudinally upon variations inpressure of the oil passing through said tube.

' by variations in pressure of the oil passing through said tubeconnecting said pipe and tube to move them relatively longitudinally.

4. An oil burner comprising an air pipe having a constricted dischargeopening, an oil tube for the passage of oil therethrough under pressurelongitudinally movable in said air pipe and arranged coaxially therewithand having a discharge end in one position fitting closely saidconstricted opening, whereby the relative longitudinal position of saidpipe and tube determines the rate of air discharge and means operated byvariations in pressure of the oil passing through said oil tube,connecting said pipe and tube to move them relatively longitudinally.

5. An oil burner comprising an air pipe, an oil tube for the passage ofoil therethrough under pressure longitudinally movable in said air pipe,said pipe having an air discharge end and said tube having an oildischarge head thereon closely fitting said pipe discharge end in onelongitudinal position to control the discharge of air from said air pipeat a rate determined by the relative longitudinal positions of said pipeand tube, constantly operating means tending to move said pipe and tuberelative to each other and means operated by variations in pressure ofoil passing through said tube to move said pipe and tube in the oppositerelative direction.

6. An oil burner comprising an air pipe, an oil tube longitudinallymovable therein arranged coaxially therewith, said pipe having an airdischarge end and said tube having an oil discharge head thereon closelyfitting said pipe discharge end in one longitudinal position todischarge air from said air pipe at a rate determined by the relativelongitudinal positions of said pipe and tube, means constantly tendingto move said pipe and tube relative to each other, a diaphragm centrallyattached to said tube and perimetrically to said pipe, a closed chambermember attached to said pipe and surrounding said tube, said diaphragmforming one wall of the chamber, the wall of said tube having openingsleading into said chamber, whereby changes in the pressure of the oilpassing through said tube move the diaphragm in opposition to the meanstending to move said pipe and tube and thereby vary the rate of airdischarge.

7. An oil burner comprising an air pipe having a constricted dischargeopening, an oil tube therein coaxial therewith, a tube between said airpipe and oil tube to shield said oil tube from the air in said air pipe,said shield tube having guides thereon adjacent the discharge end of andsupported from said air pipe, a discharge head on said oil tubeextending through and supported by said guides, and means including saidhead to regulate the discharge of air around the oil discharged fromsaid head.

8. An oil burner comprising an air pipe having a constricted dischargeopening, an oil tube therein coaxial therewith, a tube between said airpipe and oil tube to shield said oil tube from the air in said air pipe,said shield tube having guides thereon adjacent the discharge end of andbeing supported from said air pipe, a discharge head on said oil tubeextending through and supported by said guides, said oil tube and headbeing longitudinally adjustable in said guides, and means including saidhead to regulate thedischarge of air around the oil discharged from saidhead, the rate of the discharge being varied by changing the relativeposition of said head and opening.

9. An oil burner comprising an air pipe having a constricted dischargeopening at one end thereof, an oil tube therein coaxial therewith havingan enlarged head in one position fitting closely said constrictedopening at the discharge end thereof, a shielding tube between said pipeand oil tube having guides thereon supported by said air pipe and onwhich said oil tube is longitudinally adjustable to vary the rate of airdischarge between the constricted opening and en-v larged head, saidhead separating the oil and air until both have left the burner.

ANDREW J. FISHER.

